Water On The Land Flashcards
Describe the cross profile of a rivers lower course
Very wide, almost flat valley, very wide, deep channel. Gentle gradient.
What does a rivers long profile show?
How the gradient changes over the different courses
Name the river course where vertical erosion is dominant.
Upper course
Name two processes of transportation
Traction
Saltation
Suspension
Solution
When does deposition occur?
When a river slows down
Where is the current fastest on a meander?
On the outside of the bend
Name the landform created when a meander is cut off by deposition
An Ox-bow lake
Where do waterfalls form?
Where a river flows over an area of hard rock followed by an area of softer rock
What is a flood plain?
This is the wide valley floor on either side of a river which occasionally gets flooded
Describe how levees are formed
These are natural embankments along the edges of a river channel. During a floor, eroded material is deposited over the whole flood plain. The heaviest material is deposited closest to the river channel, because it gets dropped first when the river slows down. Over time, the deposited material builds up, creating levees along the edges of the channel.
What do the contour lines on map show?
The direction which a river flows.
Give two pieces of map evidence for a waterfall
The symbol for a cliff and the close contour lines
What is river discharge?
The volume of water flowing in a river
How does impermeable rock effect river discharge?
There’s a lot of runoff. Lag time is decreased so discharge increases.
Describe two physical factors that can cause floods
Prolonged rainfall
Heavy rail
Snowmelt
Relief rainfall
Name two human factors that cause flooding
Deforestation
Building construction
Name a flood that happened in a rich part of the world
Carlisle
Give an example of a flood that happened in a poor part of the world
South Asia (Bangladesh and India)
Define hard engineering
Man made structures built to control the flow of rivers and reduce flooding
Define soft engineering
Schemes set up using knowledge of a river and its processes to reduce the effects of flooding.
Describe how channel straightening reduces the risk of a flood
Water moves out of the area more quickly because it doesn’t have to travel as far
Describe the disadvantages of flood warnings
They don’t stop a flood. Also makes it hard to get insurance. People may not have access to warnings.
